Dietary Fiber, Yogurt May Lower Lung Cancer Risk

Study finds prebiotics and probiotics may protect against lung cancer.

A new epidemiology study published in JAMA Oncology reports that high dietary fiber and yogurt consumption is associated with reduced lung cancer risk.

“This inverse association was robust, consistently seen across current, past and never smokers, as well as men, women and individuals with different race/ethnic backgrounds,” said lead investigator Xiao-Ou Shu, M.D., Ingram Professor of Cancer Research at Vanderbilt University Medical Center.

Jae Jeong Yang, Ph.D., a visiting research fellow from Seoul National University in South Korea and Danxia Yu, Ph.D., an assistant professor in the Department of Medicine at Vanderbilt are co-first authors on the study.

A Synergistic Association

More than 1.4 million adults from 10 prospective cohort studies across the United States, Europe and Asia, were involved in the study, making it the largest prospective study to date to investigate the association of dietary fiber and yogurt consumption on lung cancer risk.

The highest intakes of these lung cancer-fighting foods were individually associated with a 17 percent and a 19 percent reduced risk of lung cancer, respectively, even after controlling for smoking status and pack-years, dietary confounders and other risk factors.

The study suggests yogurt and fiber may work together to further reduce lung cancer risk. When considered jointly, high consumption of both yogurt and fiber was associated with a 33 percent reduced risk of lung cancer, indicating a synergistic association.

The inverse association of lung cancer risk with fiber and yogurt consumption was particularly pronounced for individuals with squamous cell carcinoma and proinflammatory conditions, suggesting that the beneficial effect of fiber and yogurt on lung carcinogenesis may be via an anti-inflammatory mechanism, Shu said.

Prebiotics and Probiotics

Shu explained that the health benefits of fiber and yogurt as lung cancer-fighting foods may be due to their prebiotic and probiotic properties.

As a prebiotic, dietary fiber is nondigestible by humans and is instead fermented by gut microbiota into short-chain fatty acids. Short-chain fatty acids influence host immune responses, inflammation, and metabolism, not only in the gut but in far-reaching organs.

Yogurt and other probiotics, like kefir and kombucha, contain live microorganisms that help maintain a healthy gut microbiome and aid in digestion.

“Our study provides strong evidence supporting the U.S. 2015-2020 Dietary Guidelines recommending a high fiber and yogurt diet.”

Outlook

The beneficial effects of diets high in fiber and yogurt against cardiovascular disease and gastrointestinal cancer are well-established, and people are increasingly turning to prebiotics and probiotics as a way to aid in their overall health.

Shu’s findings suggest a protective role against lung carcinogenesis may be added to the list of health benefits associated with increasing fiber and yogurt intake.

“Our study provides strong evidence supporting the U.S. 2015-2020 Dietary Guidelines recommending a high fiber and yogurt diet,” Shu said.